Level controlled switch mechanism



March 9, 1954 L, 1 KMlEClK 2,671,834

LEVEL CONTROLLED SWITCH MECHANISM Filed Jan. 23, 1952 4 Sheets-Sheet l March 9, 1954 KM|E|K 2,671,834

LEVEL CONTROLLED SWITCH MECHANISM Filed Jan. 25, 1952 '4 sheets-sheet 2 l.. J. K'MlEclK LEVEL coNTRoLLED SWITCH MECHANISM March 9, 1954 4 Sheets-Sheet 5 Filed Jan. 23, 1952 11gVENToR. Zea/wld JjfmecL/a, BY

March 9, 1954 J. KMlEclK LEVEL coNTRoLLED SWITCH MECHANISM 4 Sheets-Sheet 4 Filed Jan. 23, 1952 L T i;

Patented Mar. 9, 19r54 LEVEL CONTROLLED SWITCH MECHANISM Leopold J. Klnjecilr,` Chicago, Ill., assignor to McDonnell & Miller', Inc., Chicago, Ill., a corporation of Delaware Application January 23, 1952, Serial- No. 267,891

(Cl. 20o- 84) 8l Claims. 1

The present invention relates to control mechani'sm for switches adapted to be actuated by means responsive to variations in liquid leveli or other means responsive to one or more vari ables in which the variation is gradual. The present invention krinde its preferred embodimentA in a high pressure, low water, cutoff and pump control mechanism for boilers and the like.

Certain of the teachings are applicable to the operation of` control elements, such as switches which are subject to control in accordance with liquid level in various pressure vessels, such, for instance, asA boilers, stills and' other liquid containers subject to pressure and/or temperature; 'I'he switch operating mechanism is useful for operating, with snap action, one ormore switches by motion of a member which moves through a range of positionsV of greater: amplitude than, that of the movable switch member; Certain other phases oi?v the invention are applicable generallyv to securingresponse of a switchl or' valve to'fluctuu ations of position ofv a controllingA member Whether the. same be due to liquid` level or other phenomenon, particularly where the controlling member is separated from the switcher' valve actuating mechanism by` an intervening; fluid tight wall'.

Switches and valves, responsive to variations in level' of water or other liquids in a steam4 boiler: are known. The most widely utilized devices on the market at present involve the use of a iiexiblemetal' bellows for sealing the jointA between the movable part andthe pressure enclosure in which the float is contained, and whereinpressure is tobe retained'. For; low pressure work, the use of theflexible bellows as a seal for themotion transmitting partsis satisfactory, but when high pressures, such as 250 pound gauge or higher is involved, the metal bellows seal is inadequate', since thev area exposed to pressure develops forces which the metal bellows seal cannot adequately sustain or the oat mechanism cannot overcome.

It isan aimA of" the present invention to provide a sealed` floatv responsive switch actuating mechanism. capable of*l satisfactory operation underv pressures; which. cannot satisfactorily be with-- stood by iieXible metal bellows orr other knownsealing means now* customarilyV employed for low pressure work. While low pressure andi high pressure. are'relative terms, there is certainlyV a difference in the problem presented by a heating boiler with ar guage pressure of' 15 to 20'- pounds and a power boiler carryingV a guage pressure of 250'- pounds. Manymunicipal codes' require anengneerin. attendance of a boiler carrying steam solders or affect the strength or flexibility of the metal of the bellows.

Another aspect of the present invention, whichl is of marked advantage, is the novel organiza-l tionand arrangement of the elements of the magnet system therein for causing the operationof a switch actuator located outside the presv sure vessel, in response to motion of a magnetic member inside thel pressure vessel. Another novel feature of the mechanism embodying' theI present invention is a new arrangement of twoA or more magnetic switch actuating members responsive to a common magnetic member which moves in response to water level changev or othervariable controlling phenomena. According to the present invention, it is possible to-arrangetwo or more such switch actuators to be operated successivelyl and without interference with each other,k each independently adjustable"A as to the differential within which the same may respond. The primary magnetic member which moves in accordance with water levelchanges may have a substantially longer travel than the travel ofl` the switchactuator' or secondary magnetic member-n The present invention also permits adjustn'rentv of the range of response: of the secondary mag-- netic member.

Another novel feature ofi the: magnetic system. of the presentV invention resides. in the biasing', meansfor holding the switchactuatoror-secon ary magnetic members in eithery of twoextreme positions so as to insure adequate and, reliabley contacting pressure between a movableY Contact carried by the secondary magnet and. stationary contacts of. the switch. means. which is. actuated. thereby. This biasing. means is inthe. preferred,

embodiment,y a, pair of magnetic armature members which. are also utilized as adjusting screws or stop screws for controlling the diiierential within which the switch actuator magnet is permitted to move.

A basically new feature of the present invention resides in the disposition of the level actu- Y ated primary magnetic-member in an air or-vaifior dome above the level of the liquid whereby the air gap within which the primary magnoticmember is caused to move will not be subject to the deposit of solids from the boiler water or other liquid involved in the installation, nor will magnetic particles, such as iron particles or scale, be carried by the boiler water or other liquid into such air gap where it might clog the motion of the said magnetic member.

A still further feature of novelty resides in the relative position and motion of the switch actuating secondary magnetic member and the level responsive primary magnetic member. In the preferred embodiment, the level controlled primary magnetic member is caused to be moved up and down vertically in a substantially straight line, as by a parallel motion linkage, whereas, the switch actuating secondary magnet swings up and down on a horizontal pivot. The magnetic members present like poles nearest to each other, and the actuation of the switch actuating secondary magnet by the primary magnet is by a repulsion effect of like poles. The advance of the end of the level responsive primary magnet past the center of the pole of the switch actuating secondary magnet produces a sharp reversal of forces at a very deiinite point or position in the motion of the movable level responsive member to throw the switch with a snap action. This latter feature is accentuated by the biasing armatures, which hold the switch actuating magnet in either extreme position, provide a retarding force which holds the secondary magnet up to a certain definite point, and then very sharply yields and decreases as the primary magnet passes the center of the magnetic eld of the adjacent pole of the secondary magnet.

'I'he device of my invention may be organized to be located directly on the boiler, as, for example, at the central part of the same in connectionwith a marine boiler, so as to be subject to a minimum of oscillation due to variations in water level from the motion of the ship. It also may be mounted on any boiler` or pressure vessel in such position that the float lies on the design water level. The mechanism further may be disposed in, or as a part of, an auxiliary float chamber connected to the boiler so as to have the level therein respond to the level in the boiler. Also, the device of my invention may be provided with means for damping the motion of the level responsive magnet or of reducing the actual motion of the same by motion reducing means.

'There are certain other novel features in the details of construction which will become apparent from the following description and from the claims hereto appended.

Now in order to acquaint those skilled in the art with the manner of constructing and operating a device embodying my invention, I shall describe, in connection with the accompanying drawings a specific embodiment of the same and its mode of use.

In the drawings:

Figure l is a front elevational view in cross section illustrating a first embodiment of my new and improved level controlled switch mechanism bearing the novel features of my invention;

Figure 2 is an end elevational view of the mechanism illustrated in Figure l of the drawings;

Figure 3 is a front elevational view in cross section of a second embodiment of my new and improved level controlled switch mechanism bearing certain improved modifications therein over the mechanism illustrated in Figures 1 and 2 of the drawings; and

Figure 4 is an end elevational view of the mechanism illustrated in Figure 3 of the drawings.

Turning now to the details of the mechanism as illustrated in Figures l and 2 of the drawings, it will be recognized that a mechanism IIJ, therein illustrated, comprises generally a iioat assembly I I, a parallel linkage assembly I2, a switch housing I3 and a switch assembly I4 contained within the housing I3. 1

The float assembly II is composed generally of a spherical, hollow iioat member I5 made of stainless steel, or like corrosive resistive material and to which is attached a cylindrical actuating rod I6 by means of a suitable connector II. It will be noted that the actuating rod I6 projects outwardly of one side of the iloat member I5 and is to be supported in a substantially vertical'position for rectilinear actuation by means of the parallel linkage assembly I2 as will now be described.

The parallel linkage assembly I2 includesa vertical support post I9; the upper end of which is received and connected to the underside of a substantially circular pressure closure plate 20, atop of which the switch housing I3 is mounted, and which is anchored over an opening 2| formed in a boiler wall 22. To facilitate ready attachment of the upper end of the support post I9` to the closure plate 20 at a position offset from the central axis thereof, a collar member 23 is utilized, such being press fitted or keyed to the upper end of the support post I9 and attached to the underside of the closure plate 20 by means of suitable stud bolts 24 or the like. It will be noted that the extreme upper end of the support post I9 is received in a piloting opening formed for that purpose in the closure plate 20. A pair of bifurcated arms 26--26 are supported in substantially horizontal parallel spaced relation for pivotal movement on the vertical support post I9 by means of a pair of spaced mounting collar members 28 which are rigidly connected to the sup-` port post I9 by means of cross connecting pin` members 29. Each of the supporting collars 28 is provided with an upwardly extending arm portion 30 having a trunnion member 3I positioned transversely of its upward end for pivotal connection with a bifurcated arm 26 by means of a trunnion pin 32. It will be noted that each 4 of the bifurcated arms 26 is provided with an opening 33 adjacent one end for the reception 1 therethrough of the vertically disposed support post I9. Further, each arm 26 is provided with a central opening 34 for receiving the vertically disposed actuating rod I6 to permit` the free pivotal movement of the bifurcated arms relative to the support post and the actuating rod.

Connected to the outer, or freely movable end,. of each of the bifurcated arms 26 and therebe-l neath is one of a pair of short connecting rods 35 and 36. The upper connecting rod 35 is pivotally joined at one end to the upper bifurcated is likewise pivotally supported on the freely movable end of the lower bifurcated arm by means of a similar pivot pin 31 for like parallel movement with rod 35. Further the lower connecting rod is somewhat angularly offset in configuration: While the upper connecting rod 35 is a straight jj rod. Each of the connecting rods 35 and 36 is rigidly connected at its inner end to the cylindrical actuating rod I6 so that the two rods move acuosa.

11i-parallelism carrying the actuating rod vertically-7 therewith. Specifically, the upper connecting rodi 35 is connected toI actuating rod |561 by meal-'1sz eff a connectingy pinmember 38 and! the lower connecting rod 3S is connected; to the actuating rodi by an internally threaded; collar formation at its inner end which: threads onto the connector tl; associated with oat4 member I5'.

Since the conditions` under which the iloat and' linkage assemblyv ISI? and I2, respectively, operateare such as to cause marked deterioration and? corrosion thereof inthe presence of 'the liquids and atmosphere within the boiler chamber into which such are inserted, it is preferable that the various parts of these two assemblies be made ci a suitable antifrust orI non-corrosive material, suchY as stainless steel, brass or various copper alloys; Further, it will be appreciatedthatv since it. is desired that the float assembly be movable with a. substantially vertical rectilinear motion, the. parallel linkage assembly gives. rise to they desired actuation of. the oat assembly while supporting such in a compact and eiiicient manner. In particular it will be appreciated that sinceA thev actuating rod is supported on the support' post I9 bymeans of the cppositely directed. connecting rods and bifurcated arms, the latter ofwhich are pivotally connected at one end to the support post` and reach across the path of movement: of the actuating rod, the path orf movement of the float assembly is parallel to the chordal paths described' by the arcuate travel of the parallel arranged bifurcated: arms. Since the bi-'Eurcated arms Ziare of a substantially extended length and are arranged to describe a large radius of movement, itv will be appreciated that within the travel limits for which the float assembly and linkage assembly are designed to operate. the movementlofv the float assembly is substantially rectilinear and vertically up and down as desired.

In order that the iioat assembly, which is responsiveto variations in liquid levels within the boiler,l might -be effective for actuating the control switch assembly: I housed within the switch housing assembly I3, a primary magnet 4I) is mounted coaxially at the upper end of the actuating rodL I6; T0 this end the bar magnet 49 is housed within` a non-magnetic sleeve.4`!,made of brass,` bronze or other suitable non-magnetic material, and is provided with an internally threaded plug 42 at itsY lower end for threading connection With the upper end of actuating rod |61,` as illustrated.

To enable the bar magnet lill, which is rectilinearly movable with the float assembly, to move within the switch housing assembly I3 in actuating` the switch assemblyA I4, I have provided an upwardly extendingtubularV air or vapor dome 45 located centrallyl of andl extending through theA closure plate-v The dome 5. acts as an eiectiveseal for isolating the interior of the switch*L housing I3` from the high pressures existent within the boiler into which the float and linkagey assemblies extend. It will be appreciated that the-Vapor dome 4'5 comprises a substantially tubular non-magnetic brass or bronze member sealed atits upper end by a wall member It and open at itslower end for the axial reception therein.V of jthe upwardly extending' primary magnet MJ. This arrangement effectively seals oiT the interior ofthe switch housing I3 from the atmosphere and pressure within the boiler to which the, mechanisn'r I0' isattached; To; insure a completely 511.01." the like.

nect. theswitcli assembly It, housed in the switch 6.* dome4'5. and the clOSu-repl-'atev 20;, these two-members may bebrazed or otherwisetightlyfintercon nected to form an airV tight seal therebetween.

The switch housing: I3 comprises a substantially rectilinearbcx-like wall section comprising four rectangularly arranged walls suitably connected to4 the closure plate member 2-0- by' housing assembly t3, suitable conduit entries --551 are. provided in the cover member 53l for the reception of current conducting conduits in a conventional manner.

Disposed beneath. the top covery plate 531 and' connected' tothe housing section 5B: by a plurality of stud bolt connectors Eil is an insulated ter-- mina); plate EI. carrying pairs. of terminal connectors. screws B2, 63'. 54 and 65: there being-fl eight such terminal connector screws provided the. particular embodiment of the mechanism il lustrated herein, with such being arranged in coacting pairs bearing like numbers Figures 1 and: 2.` It; will be appreciatedl that the pairs of. terminal connector screws. (i2 and 83: arearranged in aseparated group of'four from a like group of' four comprising the pairs of terminal connector screws 6131 and 85, such` twou groups being disposed on opposite sides ofthe insulated terminali plate Si.. as shown in. Figure 1.

Mounted in depending relation, immediately below each of the groups of' terminal connector screws and connected; to the terminal plate `Iii-I.' by means of stud bolts 69, 69. are4 cooperating pairs of spaced bracket. arms. 10, 'Iufor supportv ing secondary switch magnets. 'I5 and I6 forpivotal, movement therebetween. In particular it'r will be. recognized thatl each of the cooperating pairs of depending bracket arms 'I0 pivotally'sup.- port amagnethousing 'Il between the lower ends thereof by means ot pivot pin memberv '12; lilachl of the magnet holding brackets. 'II receives. a. secondary bar magnet 'I5 or 1.6 axially there.-

' through and tightly grips the samey so that. thel magnet` moves pivotally with. its supporting bracket member between the dependingly.l are ranged supportarms 10, 'I'.B: To: accommodate thebestperformance of the mechanism ofr'my invenf-k ti'on it ispreferable that the secondarymagnets 'I5 and 'Mi be. arranged so that they have like: poles.: adjacent opposite sides of` the air dome 415, with such like poles beingof likepolaritywith the upper pole of the primary bar magnet 46 carried at the upper end of the actuating rod I6. By-this:

arrangement actuation ofl the secondary magnets by the primary magnet is effected thrcughrepul sion,` as will be amplified later herein.. Further, each of the secondary magnet holding brackets. 1 I1 is` provided with a transversely extending limit: bar 'I1 positioned adjacent the sidel walls: ci?` the. switch housing section 50;

In order that the pivotal movement of the seconda-ry magnets may be limited to desired values; cooperating pairsy ofl vertically displaced adjust'- ing screws 18 and IS are threadingly` arranged through the side walls of the housing section 50.? to project inwardly of' the latterY forproviding. adjustable limitl stops; which. contact: ther. transl tightv junction between thee tubular air' or vapor I5l versa stopy plate i Off the associate@ seclmdm' magnet mounting means to limit the pivotal throw of the secondary magnets. It is preferable that the stop screws 18 and 19 be of a magnetic material so that there is attractive coaction between each of the stop screws and the adjacent polar end of the secondary `bar magnet 15 or 16 associated therewith. This latter feature insures positioning of the secondary magnets at their throw limits to gain positive and steady contact pressure between the switch actuating means carried by the secondary magnets and the stationary contacts of the switch assembly, las will appear presently.

Mounted to the upper side of each of the secondary magnet holding brackets 1| are the immediate switch closing means referred t above. comprising pairs of resilient contact arms 89 and .8| associated With their respective magnets and 16. As will be appreciated from an examination of Figure 2 of the drawings in particular, each of the contact arms 80 and 8| comprises a resilient leaf-like member attached to one of the magnet holding brackets by stud bolts 83 and extending transversely upward therefrom. Each of the contact arms further is provided with a silver contact button at its upper end, as buttons 84, 84 on the contact arms 89, or buttonsv 85, 85 as on contact arms 8|. The associated or paired contact arms are further interconnected at their lower ends and made of a suitable electrical conductor material. `Other forms of the contact arms 88 and 8| may Ibe used so long as the essential principle involved therein of having a construction capable of 4bridging the separated pairs of contact terminals 62 through 65 is assured for closing circuits therethrough. The several pairs of contact terminals numbered 62-65 are provided at their lower ends with dependingly mounted contact supporting lingers 88, 89, 99 and 9|, respectively, which support silver contact buttons 92, 93, 94 and 95 aligned properly to permit circuit closing contact with the pairs of silver contact buttons 84 and 85 mounted at the upper ends ci. the arcuately movable contact arms 88 and 8 From the `above it will be recognized that rocking actuation of the secondary magnet 15 in the appropriate direction `permits alternate circuit closure between the cooperating pairs of contact buttons 92 associated with the paired terminals 52, 82 or circuit closure through contact buttons 89 associated with the paired terminal connectors `63, 63. Likewise rocking actuation of magnet 16 permits circuit closure between contact buttons 94 connected to terminals 64, 64 or contact closure between terminal buttons 95 :associated with terminal connectors 65, 65.

In the preferred `installation of a level responsive switch mechanism I0, as I have set forth above, the pair of contact terminals 62 are designed to be connected in series with a relay coil or the like in a contact starter associated with the water supply ipump of the boiler. The pair of separated contact terminals 63 are to be connected in circuit with a visual or audible alarm system of a conventional design, for indicating the operating condition of the boilers water supply pump. The separated contact terminals 6I 4are to be connected in circuit with the contact starter or relay associated with the burner circuit of the boiler so that when such are bridged `by the coacting contact arms 8| to close circuit therethrough, operation of the burner will take place. In order to indicate the operating condition o1 the boilers burner, the contact termi- 75 nals 65 are connected in circuit with a second visual or audible alarm signal -system to indicate to the operator whether or not the burner is in operation. Other arrangements and connection of the several terminals provided inthe switch assembly may be util-ized readily and will vbe suggested to one familiar with this art, since the specic uses to which such have lbeen applied herein are for illustrative purposes only and are not intended to bea restriction on the use of my mechanism.

In the normal operating condition of the boiler and my mechanism, as illustrated in Figure l of the drawings, it will be noted that the polar end of the primary magnet 48, herein illustrated as being the north polar end thereof, is positioned slightly above the center of the secondary magnets 15 and 16. Further it will be appreciated that secondary magnet 15 is positioned slightly above the secondary magnet 16; this latter feature to bring about a desired sequential operation of the switch circuits as will be explained presently. In this position of the several magnets, 40. 15 and 16, the north polar end of the primary magnet 40, being slightly above the axis of the north polar end of the secondary magnet 15, causes a counterclockwise rotation of the latter magnet 15, as viewed in Figure 1, due to the repulsive effect between the like poles thereof. Therefore, it will be recognized that when the pair of connective terminals 63 have their contact buttons 93 bridged by the pair of contactor arms 80, circuit is closed therebetween to energize the visual or audible alarm system associated with the water supply pump of the boiler. Further, in this condition of circuit closure through contacts 63, the stop bar 11 associated with magnet 15 abuttingly engages the lower regulating screw 19 positioned adjacent thereto to bring the south polar end of magnet 15 adjacent the upper stop screw 18 for magnetic attraction therewith. Likewise, the secondary magnet 16, with its north polar end adjacent the air dome I5, is repulsed by the north polar end of the primary magnet 4U to move the contactor arms 8| clockwise thereby closing circuit between the contact buttons 94 to turn on the boilers burner. So long as the water level, designated WL in Figure 1,

is maintained at the designed operating level as illustrated, the above described Figure 1 conditions of the switch assembly prevail. Upon a gradual lowering of the water level within ythe boiler, however, the float assembly moves respon sively downwardly until the north polar end of 15 and the upper adjustingv screw 18 to pivotally actuate the contact arms 8|) clockwise closing the circuit through contacts 92 to energize the water supply pump. This latter movement is accelerated somewhat by the magnetic attraction between magnet 15 and the vadjacent adjusting screw 19, as the south polar end of magnet 15` moves out of its magnetic attractive position with the uppermost adjusting screw 18 and approaches a magnetic attractive position with the lowermost adjusting screw 19. Also it will be appreciated mechanism i il.

..- thatonce contact is closed through contacts 92 f or 93, the attraction of the magnet 15 for the adjacent adjusting screw serves to maintain good contact pressure between the movable and stationary contacts to eliminate contact flutter in the switch assembly. Upon closure of the circuit through the terminal connectors yE2, the water supply pump furnishes water to the boiler to raise the water level therein.

If the movement of the float assembly continues downwardly to a point where the north polar end of primary magnet B passes the axis of the secondary magnet 1li, repulsive effect between the like polar ends of the primary magnet and the secondary magnet 'it causes a corresponding counterclockwise actuation of the secondary magnet l. This movement serves to open the circuit through terminal connectors dii, shutting down the boilers burner followed. by a bridging of the contact buttons 95 to close the circuit through the terminal connectors 55 for energizing the visible or audible alarm system in circuit therewith, indicating the shutting off of the burner. Again magnetic attraction between the south polar end of magnet 'iS and the adjusting screws 'I8 and 'i9 brings about an improved Y functioning of the switch assembly as described above.

As the water level is raised within the boiler in response to the supply pumps operation, the float assembly will responsively move upwardly to reverse the above sequential operation of the switch assembly causing a reversal of the pivotal movement of the two secondary magnets and 'E5 and sequentially turn eff the visible or audible alarm system associated in circuit with terminal connectors E5, close the circuit to the burner in circuit with terminal connectors 64, open the circuit through terminal connectors E2 to shut down the water supply pump and close the circuit through terminal connectors 63 to energize the visible or audible alarm system associated therewith.

It will be appreciated that the desired time .delay in the sequential operation of the several circuits controlled by the secondary magnets 75 and 'iii respectively, may be regulated by the vertical spacing of the pivotal axesl for such secondary magnets and by the adjustment in or .out of the adjusting screws i8 and lil, thereby ,to regulate the throw necessary to make and break the circuits associated with the pairs of terminal connectors |52 through 55. Thus it will be recognized that great flexibility in operating characteristics and design is readily obtained with the mechanism lil, as l have set forth herein.

In Figures 3 and /i of the drawings I have illustrated a secondary or modied form of my invention which is directed to a water or liquid level responsive switch mechanism similar to that heretofore described, except that such is to be mounted within an auxiliary float chamber instead oi directly into the interior of the boiler in contradistinction to my previously described modified switch mechanism |00 embodies similar principles to those described heretofore and that its operating characteristics are of a lille character with the switch mechanism lil, illustrated inpieurcs l and 2. l

in particular it will be'noted that the modified switch mechanism |00 is to be mounted in1an It will be appreciated that they l0 auxiliary float chamber 0 and comprises a oat assembly I||, a linkage assembly H2, a switch housing assembly I I3, and a switch assembly I I4 disposed within the switch housing assembly I I3. Since there are several slight variations illustrated in my mcdied mechanism mi), 1 shall now describe its features.

It will be noted that auxiliary float chamber Il@ is provided with a plurality of pipe connective openings A, B, C, D and E of which opening A is utilized for connection with the steam space above the water level within the boiler with which such is associated, opening B communicates with the water space in the boiler for supplying water to the auxiliary iioat chamber, opening C is utilized as a drain or blow-off connection and openings D and E. are provided for mounting a conventional sight glass or gauge therebetween to indicate the water level within the auxiliary float chamber or may be closed 'orf if desired, all in a conventional manner.

The oat assembly of my modified mechanism lili] comprises a spherical float ||5 having an internally threaded connector v| I1 brazed or otherwise rigidly connected to its outer surface, for receiving the lower end of a threaded connector plug II. Otherwise the oat assembly III of this modied mechanism is substantially the same as that heretofore described for my mechanism lil.

However, the linkage assembly ||2 which 'supports the float assembly for vertical up and down or rectilinear movement differs slightly from the corresponding assembly described for my mechanism ||l. In particular it will be observed that linkage assembly i2 is designed to afford a reduction between the movement of the iioat assembly and the primary magnet responsively actuated thereby. To accomplish this, a vertical support post I i9 is mounted -dependingly from the lower side and slightly off center of -a closure plate |25 which is fitted tightly over and to the upper end of the auxiliary iloat chamber to provide an effective seal thereover, much as in mechanism I0. Support post I |9 is carried at'its upper end by a collar member |23 fastened to the underside of the closure plate l2!! by means of stud connectors |24. A pair of parallel spaced channel-shaped bifurcated arms |26 are pivotally connected at one end to collar members |28, which in turn are rigidly secured in vertical spaced relation on the support post ||9 by vconhector pins |23. Each of the collar members |28 has an upwardly extending arm portion |39 which is integrally formed with a transversely disposed runnion portion |3I for pivotal connection with one of the bifurcated arms by means of pin connectors |32, all in a manner very similar to that utilized in mechanism |23 heretofore described. However, it will be noted that each of the collar members |23 is provided with an Iinwardly extending stop portion |33, disposed on the opposite side thereof from its upwardly extending arm portion and that such stop portions |33 are disposed beneath the bifurcated arms |26 in the mounted position of the collars |28 on the support post. The stop members |33, of course. interfere with the arms `|23 thereby serving to limit the downward arcuate movement of such overlying bifurcated arms |26.

Connection between the outer ends of the bifurcated arms and the float assembly III is accomplished by means of a pair of like short connecting rods |34. Each connecting rod |34`is directed toward the support post H9 and `be- 11 heath the bifurcated arm |26 to which such is pivotally connected. Connection between the inner ends of the short connecting rods |34 and the iloat is accomplished by means of a tubular member |35 which is threaded to the upper end of plug ||8 and rigidly connected to the rods |34 by peened over pin members |36. It will be appreciated that this connection means between the connecting rods and the float assembly is somewhat different from that heretofore described for use in my mechanism I0 but I have found that a connecting arrangement of this order particularly assures an accurate parallel spacing of the two short connector rods |34 and gives a ready and simple means for connecting the inner ends thereof rigidly to the float assembly, as is desired.

means of pin and cotter key connectors |38 for `maintaining such arms in a desired parallel spaced relation. It further will be noted, from Figure 4 in particular, that the extension member |31 comprises a substantially U-shaped metal stamping having a pair of separated arms |35, |39, each of which is pivotally tied by connectors |38 to the adjacent side of the bifurcated arms |26.

Mounted to the upper end of the extension member 31, so as to be positioned in a vertical disposition and slightly oiset toward the support post I9, from the axis of tubular member |35, is a primary bar magnet |40. The magnet |40 is connected to the upper end of the extension member 31 by means of a tubular sleeve |4| press tted coaxially over a lower connecting plug |42, which in turn is riveted solidly to the upper end of member |31. This arrangement of the Alinkage assembly and the primary magnet |40 provides a reduction in the responsive vertical up and down motion of the primary magnet over the vertical up and down motion of the float assembly, in contrast to the linkage and oat assembiles of the previously described mechanism |0, so that the rectilinear movement of primary magnet |40 is not of like amount with the vertical movements of the liquid level responsive float assembly.

Mounted centrally through the closure plate |20 is a tubular vapor or air dome |45 projecting upwardly into the switch housing ||3 and which is attached with a sealed connection to plate 20 by means of a threaded connector |46, as illustrated. Air dome member is integrally closed over at its upper end and open at its lower end to provide a seal between float chamber I0 and the interior of the switch housing |3 for receiving the upwardly extending primary magnet |40 through its open lower end.

Preferably the float and linkage assemblies .described heretofore are to be constructed of ,non-corrosive materials, such as brass, bronze .or stainless steel, and the parts associated with -the primary magnet, such as the tubular mem- Aber |4|, plug |42 and the air dome |45 are of a non-magnetic material such as brass or the like. The closure plate |20 suitably may be formed of a brass or bronze as in my mechanism i0, illustrated in Figures 1 and 2 of the drawings.

The switch housing assembly ||3 is constructed of brass or bronze and mounted atop the closure plate |20, as with the housing assembly I3 of my rst described mechanism I0. A removable terminal cover plate |41 is also provided to cover over the upper end of the side wall portion |48 of the housing assembly; such being connected thereto by a plurality of vertically disposed and threadingly engageable locking studs |49, all as in the housing assembly of mechanism I0. An internal terminal plate |50 of an insulating material is provided immediately below cover plate |41 and such is attached across the upper interior of the housing side wall portion |48 by means of a plurality of stud connecting bolts I5! or the like. Pairs of terminal connectors, eight in number and numbered |52, f

|53, |54 and |55 are arranged in cooperating spaced pairs in the terminal plate |50. Also mounted in depending relation from the center of the terminal plate |50 is a yoke member |56 comprising two separated arm portions |51 each of which is provided with an enlarged aperture |58 for receiving one end of a secondary magnet therethrough for reasons which will appear presently.

As in the mechanism |0 of Figures 1 and 2, the switch assembly ||4 of my modied mechanism is housed within the switch housing assembly I3 and comprises a pair of magnetic switch actuators having secondary bar magnets |60 and |6| held for pivotal actuation by brackets |62 supported between pairs of separated depending support arms |63. The secondary magnets are again arranged with their like magnetic poles adjacent opposite sides of the air dome |45 and the primary magnet |40 is arranged so that its upper polar end is of a like character with the adjacent polar ends of the secondary magnets |60 and |6|. Thus, a magnetic repulsion effect is utilized to pivotally actuate the switch actuator means, as in my mechanism |0 of Figures 1 and 2.

Vertically spaced stop screws |64 and |65 are threadingly mounted through the side walls of the housing portion |48 to limit the arcuate movement of the switch actuators and pivotally mounted bar magnets |60 and |6| by contacting stop plates |66 disposed transversely on the magnet holding brackets |62. It wili also be recognized that the yoke member |56 acts as a stop means by limiting the arcuate movement of the secondary magnets which project through the arms |51 via openings |58 therein so that even when the adjusting screws are completely removed from the housing, the secondary magnets are limited to maximum limits of arcuate movement. The stop screws, of course, also act as armatures for magnetic attraction with the adjacent polar ends of the secondary magnets, similar to the related functioning of my mechanism I0. Pairs fo resilient contacter arms |61 and |68, constructed similar to the contactor arms and 8| heretofore described, are mounted atop the magnet holding brackets |62. Each of the paired contactor arms |61 and |68 are provided with silver contactors |69 and |10, respectively, at their upper ends for making and breaking contact between associated pairs of contact buttons |12, |13,` |14 and |15 associated respec- ,13 tively with the several pairs of terminal connectors |52, |53, |54 and |55.

The use and operation of the modiiiedlevel controlled switch mechanism im), illustrated in Figures 3 and 4, are similar to that described for ymechanism I0 of Figures 1 and 2 of the drawings with the exception that the linkage assembly |2 in this modified embodiment provides a reductioi between the movement of the primary magnet and the oat assembly as described above. The several pairs of terminal connectors EEZ-|55, of course, are connected respectively in circuit, as before, with the water supply pump, the water supply pump visual or audible alarm system, the boiler burner circuit and the audible or visible boiler burner alarm system. Vertical actuation 0f the primary magnet within` the air dome |45 again eiects corresponding repulsion of the secondary magnets {Si} and ll, positioned adjacent the air dome and exteriorly thereof, to eiiect the sequential operation of the pump, alarm and boiler control circuits in e, manner as described heretofore in association with the primary embodiment of my invention demonstrated in Figures l and 2 of the drawings.

By way of general observation, and as related `to both of the embodiments of my invention described herein, it should be noted that the air domes' 45 and |45, shown in the respective mechanisms Ill and it, are of a tubular con- 'guration of a rather small diameter to airord only a slight clearance for the coaxially movable primary magnet therein. This type of 'air dome, While being constructed of rather a light material, is nevertheless capable of withstanding relatively high pressures due to its small diameter thereby adapting such for ready use with high prese sure boilers, or the like, to which my present invention is directed. Further, it should be noted that in both embodiments of my invention, the "5 tubular air domes are at all times disposed above the water level within the boiler or the auxiliary float chamber so that they are not subject to deposits of solids carried by the boiler liquid. While such domes may well trap air as well as steam within their interior, the atmosphere therein will be free of liquids carrying solids, dust particles and the like, thus maintaining the movable primary magnets substantially free of encrusting deposits which might interfere with their free operation. The vertical disposition of the air dome above the liquid level further lends to this advantageous feature oi maintaining such substantially free of depository materials carried by the liquids within the boiler.

Thus I am able to lreep the interior oi the air dome and the movable primary magnet substantially free of encrusting deposits and sclids carried by the liquids within thev boiler to minimize interference from this source with the operation of my level responsive mechanism. I am, therefore, enabled to maintain a substantially free air gap between the movable primary magnet and the interior of the air dome to facilitate prolonged and eiilcient operation of my switch mechanism as desired. y

Further, it will be appreciated that the vertical displacement of the axes of the two secondary magnets, which are influenced by the repulsive effect of the vertically movable primary magnet,

provides a simple expedient for accomplishing a sequential operation of the devices connected in electrical circuit with the switches operated in response to pivotal actuation ofthe secondary magnets while` providing a compact and veilicient construction for the mechanism involved. It also will be appreciated that the use of the air dome and the closure plate provides a convenient expedient for sealing oil the high pressures Within the boiler or auxiliary iloat chamber from the inte 1ior of the switch housing which contains the switching mechanism and must therefore be periodically opened for inspection and repairs. This latter feature also savesJ the delicate switching mechanism from the corrosive eiects of the atmosphere within the boiler and readily adapted my mechanism for use with high pressure boilers or distillation and cracking stills for which such is designed.

lt will therefore be appreciated that while I have herein shown and described two embodiments in which the features of my invention may occur, its several novel features and principles may be embodied in' related devices oi other designs without departing from the spirit and scope of teachings. rtherefore, I do not wish to be limited to the speciilc embodiments herein set forth except as may appear in the following appended claims.

I claim:

1. In a boiler control, a closure plate adapted to be subject to boiler pressure and having an opening therethrough, a tubular dome member closing said opening and extending upwardly from the plate, a primary magnet having a pole adapted to be moved up and down in said dome, a linkage connected to the plate for guiding the magnet ier substantially rectilinear motion, and a secondary magnet having a horizontal pivot supported on said plate and having a pole of the same polarity adjacent the said pole of said primary magnet whereby said poles repel each other, such magnetic repulsion causing pivotal movement or" said secondary magnet in response to movement of said primary magnet in either direction within said dome, said secondary magnet being disposed substantially horizontally `with its aforesaid pole disposed adjacent the outside sidewall ci saisi tubular deine.

2. In a device of the class described, a frame member, a substantially vertical pressure retaining wall of non-magnetic material supported on said frame, a primary bar magnet having its axis substantially parallel to wall and mounted on said frame for motion in a substantially vertical direction alcng said wall, a secondary bar magnet pivoted on said frame for swinging motion in a vertical plane with its longitudinal axis generally horizontal and having one pole disposed adjacent said wall, and the primary magnet having a like pole on the other side oi the wall at about the level ci the secondary magnet, means for rectilinearly raising and lowering the primary magnet, and actuated by pivotal movement of the secondary magnet away from said wall in response to magnetic repulsion thereof as the poles ci the two magnets approach one another during both the raising and lowering of said primary magnet.

3. In a device of the class described, a pressure retaining plate, opening therethrough, a tube means magnetically attractive with `the other.

polar end of said secondary magnet for yieldingly holding the secondary magnet at each limit of its motion, and switch means connected to said secondary magnet for actuation in response to pivotal movement of said secondary magnet eected by movement of said primary magnet in directions both toward and away from the closed end of said tube. v

4. In a boiler control, a frame plate having a substantially vertical opening, a substantially vertical tube of non-magnetic metai having its lower end seated in said opening and its upper end sealed to provide a Vapor dome, a primary bar magnet adapted to be moved up and down in said vapor dome, a parallellogram linkage means connected to the primary magnet and controlled by a oat for moving said primary magnet rectilinearly up and down, said linkage being constructed and arranged to produce a differential in movements between the iioat and said primary magnet, a secondary bar magnet disposed outside the tube in a substantially horizontal position with its axis generally radial relative to the tube, said latter magnet being pivoted on the `frame plate on a substantially horizontal axis to swing in a substantially vertical plane with one end adjacent said tube, said one end thereof being of the same polarity as the upper end of the primary magnet, and switch means connected to the secondary magnet and operable in response to movement of said one end thereof away from said tube upon the approach of the upper end of said primary magnet attending both the up and down motion of the latter within said dome.

5. In a level controlled switch mechanism of the class described, a vertically disposed support rod, a pair of parallel, vertically spaced arm members extending outwardly from said support rod and having pivotal connection at one end therewith, a pair of parallel spaced connecting rods, of a length equal to substantially onehalf of the length of said arms, each pivotally connected at one end to the outer arcuately movable other end of one of said arms, said connecting rods extending from their pivotal connection with said arms toward said support rod and in coplanar relation with said arms, and a vertically movable actuating rod, having a fioat member attached to its lower end, rigidly connected to the arcuately movable other ends of said connecting rods and extending through said arms via central registeringly aligned openings formed in the latter, whereby said actuating rod is supported for substantially rectilinear movement in response to simultaneous arcuate movement of said arms and connecting rods.

6. A level controlled switch mechanism of the class described for actuating a boiler control switching means in response to liquid level `changes in the boiler to which such is attached,

comprising in combination, a switch housing, a rigid support rod mounted dependlngly from the lower side of said housing, a pair of parallel spaced arms, each pivotallyconnected at one end to said support rod for parallel arcuate movement, an actuating rod positioned in spaced parallel relation to said support rod and movable through said two arms via central openings formed therein, a float member mounted to the lower end of said actuating rod, a magnetic switch actuating means mounted to the upper end of said actuating rod and projecting into said housing for actuating switch means mounted in said housing in response to rectilinear movement of said actuating rod, and a pair oi' parallel spaced, short connecting rods, each pivotally connected at one end to the arcuately movable other end of one of said arms and rigidly connected at its opposite end to said actuating rod, said connecting rods moving simultaneously and along like arcuate paths 'relative to said arms whereby said actuating rod and attached iloat are supported for substantially rectilinear movement in response to liquid level changes within the boiler.

7. In a level controlled switch mechanism for use in actuating a boiler control switching system in response to liquid level changes within the boiler, the combination comprising, a switch housing attachable to the boiler, a rigid support rod mounted in depending vertical relation from the lower side of said housing, a vertically disposed actuating rod positioned below said housing and in spaced relation to said support rod, a float member attached to the lower end of said actuating rod, a permanent bar magnet mounted coaxially to the upper end of said actuating rod for rectilinear movement therewith, said magnet extending into a vapor dome projecting into said switch housing and sealed therefrom for actuating switch mechanisms, mounted in said housing exteriorly of the dome, in response to vertical movement of said actuating rod, and linkage means for supporting said actuating rod, magnet and float for substantially vertical rectilinear movement, comprising, a pair of parallel spaced bifurcated arms, each pivotally connected at one end to said support rod for parallel arcuate movement, said arms traversing said actuating rod, a pair of short connecting rods, one pivotally connected to the other arcuately movable end of each of said arms for pivotal arcuate movement therebeneath and extending toward said support rod; and rigid connective means joining the other end of each of said connecting rods to said actuating rod, intermediate the ends of the latter, whereby said connecting rods are simultaneously movable with parallel arcuate motion as are said bifurcated arms, but in opposite clockwise sense to the latters movement, for eil'ecting substantially rectilinear movement of said actuating rod.

8. In a device in the class described, a frame member, a pressure retaining wall of non-magnetic material supported on said frame member, a primary bar magnet having its longitudinal axis substantially parallel to said wall and mounted for `substantially rectilinear reciprocation adjacent said wall, a secondary bar magnet pivoted on said frame for swinging motion in a plane substantially coincident with the longitudinal axis of said primary magnet, said secondary magnet having its longitudinal axis disposed generally transverse to the longitudinal axis of said primary magnet with one pole thereof adjacent one side of said wall. said primary magnet having a like pole on the opposite side of Vsaid wall at substantially the level of said secondary magnet, and switch means actuated by the pivotal movement of said secondary magnet away from said wall in response to its magnetic repulsion occurring as the poles of said two magnets approach one another during movement of said primary magnet in both directions of its reciprocal movement LEOPOLD J. KMIECIK;

References Cited in the file of this patent,

UNITED STATES PATENTS Number Name Date 927,129 Dombrowski July 6, 1909 2,292,648 Moore Aug. 11, 1942 2,495,416 McCauley Jan. 24, 1950 

